The invention relates to an airbag module.
European Patent 1 113 948 B1 (incorporated by reference herein) discloses an airbag module with a vibration damper for a steering wheel. In this airbag module, a diffuser and an airbag are fastened on a horizontal section of the module housing by means of screws. In this case, the airbag mouth lies flat between this horizontal section and the diffuser and is clamped between the two by means of the screws. In order to prevent the airbag mouth from tearing off when the airbag is deployed, the apertures for the screws in the airbag have to be of reinforced design. Furthermore, high nut tightening torques are required in order to achieve a secure clamping. This requires a great material thickness and a multiplicity of screws, as a result of which these arrangements are difficult and require a considerable outlay on installation.
Furthermore, German Laid-Open Specification 42 33 751 A1 (incorporated by reference herein) discloses an occupant restraint system, in which the airbag is fastened to a housing by means of profiled strips which can be inserted in a form-fitting manner into complementary mating profiles on the housing, with the result that fastening screws can be omitted at these fastening points. These profiled strips can be latched or locked on the mating profile in a sideways direction with respect to their longitudinal axis or can be inserted in the longitudinal direction into the mating profile. This saves on installation costs and weight because of the omission of the fastening screws.
However, this arrangement is suitable only for front passenger airbags, since the latching or locking in the sideways direction initially requires a lateral displacement over and beyond the mating profile in order subsequently to then be pressed into the latter. This is possible in the case of a front passenger airbag module, in which the housing generally has a rectangular opening for accommodating the blow-in mouth of the airbag. Since the airbag is expandable, two profiled strips running in the direction of the longitudinal sides of the housing opening can therefore easily be moved over the mating profile on the housing. The airbag is then fastened to the narrow sides of the housing in a conventional manner by means of bolts or pins.
Since, on account of the generally cylindrical gas generator, the housing of a driver's airbag module also has a circular opening on which the airbag has to be fastened, the blow-in mouth of the airbag also has to be circular. The profile would therefore likewise have to be a closed, rigid circular ring, meaning that a lateral displacement over the mating profile on the housing is not possible.
However, an insertion of the profile in its longitudinal direction is also not possible because of the circular ring shape.